JPA常见API

/** * 类似于 hibernate的persist(Object entity)方法，若对象有 id, 则不能执行 insert 操作, 而会抛出异常。 */@Testpublic void testJPAPersist() {Customer customer = new Customer();customer.setName("zhangsan");// 异常：customer.setId(100);entityManager.persist(customer);System.out.println(customer.getId());}